settings: remove about screen reliance on home

Remove the about screen's reliance on the home data.

The home view's data can no longer be trusted now due to the "hide
collaborators" setting, so now the about screen uses statistics
derived from MusicStore itself. This also avoids constantly
resumming the duration when the UI is initially created.

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -156,7 +156,7 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
 
         collect(homeModel.recreateTabs, ::handleRecreateTabs)
         collectImmediately(homeModel.currentTab, ::updateCurrentTab)
-        collectImmediately(musicModel.libraryExists, homeModel.isFastScrolling, ::updateFab)
+        collectImmediately(homeModel.songs, homeModel.isFastScrolling, ::updateFab)
         collectImmediately(musicModel.indexerState, ::handleIndexerState)
         collect(navModel.exploreNavigationItem, ::handleNavigation)
     }
@@ -373,9 +373,9 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
         }
     }
 
-    private fun updateFab(hasLoaded: Boolean, isFastScrolling: Boolean) {
+    private fun updateFab(songs: List<Song>, isFastScrolling: Boolean) {
         val binding = requireBinding()
-        if (!hasLoaded || isFastScrolling) {
+        if (songs.isEmpty() || isFastScrolling) {
             binding.homeFab.hide()
         } else {
             binding.homeFab.show()

app/src/main/java/org/oxycblt/auxio/music/MusicViewModel.kt

@@ -31,14 +31,12 @@ class MusicViewModel : ViewModel(), Indexer.Callback {
     private val indexer = Indexer.getInstance()
 
     private val _indexerState = MutableStateFlow<Indexer.State?>(null)
-
     /** The current music indexing state. */
     val indexerState: StateFlow<Indexer.State?> = _indexerState
 
-    private val _libraryExists = MutableStateFlow(false)
+    private val _statistics = MutableStateFlow<Statistics?>(null)
-
+    /** The current statistics of the music library. */
-    /** Whether a music library has successfully been loaded. */
+    val statistics: StateFlow<Statistics?> get() = _statistics
-    val libraryExists: StateFlow<Boolean> = _libraryExists
 
     init {
         indexer.registerCallback(this)
@@ -56,12 +54,35 @@ class MusicViewModel : ViewModel(), Indexer.Callback {
     override fun onIndexerStateChanged(state: Indexer.State?) {
         logD("New state: $state")
         _indexerState.value = state
+
         if (state is Indexer.State.Complete && state.response is Indexer.Response.Ok) {
-            _libraryExists.value = true
+            val library = state.response.library
+            _statistics.value = Statistics(
+                library.songs.size,
+                library.albums.size,
+                library.artists.size,
+                library.genres.size,
+                library.songs.sumOf { it.durationMs }
+            )
         }
     }
 
     override fun onCleared() {
         indexer.unregisterCallback(this)
     }
+
+    /**
+     * Non-manipulated statistics about the music library.
+     */
+    data class Statistics(
+        /** The amount of songs. */
+        val songs: Int,
+        /** The amount of albums. */
+        val albums: Int,
+        /** The amount of artists. */
+        val artists: Int,
+        /** The amount of genres. */
+        val genres: Int,
+        val durationMs: Long
+    )
 }

app/src/main/java/org/oxycblt/auxio/settings/AboutFragment.kt

@@ -25,20 +25,16 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import androidx.core.net.toUri
 import androidx.core.view.updatePadding
+import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
 import com.google.android.material.bottomsheet.BottomSheetDialogFragment
 import com.google.android.material.transition.MaterialFadeThrough
 import org.oxycblt.auxio.BuildConfig
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentAboutBinding
-import org.oxycblt.auxio.home.HomeViewModel
+import org.oxycblt.auxio.music.MusicViewModel
-import org.oxycblt.auxio.music.Album
-import org.oxycblt.auxio.music.Artist
-import org.oxycblt.auxio.music.Genre
-import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.ui.fragment.ViewBindingFragment
-import org.oxycblt.auxio.util.androidActivityViewModels
 import org.oxycblt.auxio.util.collectImmediately
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.showToast
@@ -49,7 +45,7 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
  * @author OxygenCobalt
  */
 class AboutFragment : ViewBindingFragment<FragmentAboutBinding>() {
-    private val homeModel: HomeViewModel by androidActivityViewModels()
+    private val musicModel: MusicViewModel by activityViewModels()
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -72,32 +68,25 @@ class AboutFragment : ViewBindingFragment<FragmentAboutBinding>() {
         binding.aboutFaq.setOnClickListener { openLinkInBrowser(LINK_FAQ) }
         binding.aboutLicenses.setOnClickListener { openLinkInBrowser(LINK_LICENSES) }
 
-        collectImmediately(homeModel.songs, ::updateSongCount)
+        collectImmediately(musicModel.statistics, ::updateStatistics)
-        collectImmediately(homeModel.albums, ::updateAlbumCount)
-        collectImmediately(homeModel.artists, ::updateArtistCount)
-        collectImmediately(homeModel.genres, ::updateGenreCount)
     }
 
-    private fun updateSongCount(songs: List<Song>) {
+    private fun updateStatistics(statistics: MusicViewModel.Statistics?) {
+
         val binding = requireBinding()
-        binding.aboutSongCount.text = getString(R.string.fmt_lib_song_count, songs.size)
+        binding.aboutSongCount.text = getString(R.string.fmt_lib_song_count, statistics?.songs ?: 0)
+
+        requireBinding().aboutAlbumCount.text = getString(R.string.fmt_lib_album_count, statistics?.albums ?: 0)
+
+        requireBinding().aboutArtistCount.text =
+            getString(R.string.fmt_lib_artist_count, statistics?.artists ?: 0)
+
+        requireBinding().aboutGenreCount.text = getString(R.string.fmt_lib_genre_count, statistics?.genres ?: 0)
+
         binding.aboutTotalDuration.text =
             getString(
                 R.string.fmt_lib_total_duration,
-                songs.sumOf { it.durationMs }.formatDurationMs(false))
+                (statistics?.durationMs ?: 0).formatDurationMs(false))
-    }
-
-    private fun updateAlbumCount(albums: List<Album>) {
-        requireBinding().aboutAlbumCount.text = getString(R.string.fmt_lib_album_count, albums.size)
-    }
-
-    private fun updateArtistCount(artists: List<Artist>) {
-        requireBinding().aboutArtistCount.text =
-            getString(R.string.fmt_lib_artist_count, artists.size)
-    }
-
-    private fun updateGenreCount(genres: List<Genre>) {
-        requireBinding().aboutGenreCount.text = getString(R.string.fmt_lib_genre_count, genres.size)
     }
 
     /** Go through the process of opening a [link] in a browser. */